Stores in most states, including North Carolina, can now charge customers a "checkout fee" if you use your credit card. These fees are not allowed in all states. Ten states have laws that prohibit surcharge fees on credit cards. They are California, Colorado, Connecticut, Florida, Kansas, Maine, Massachusetts, New York, Oklahoma and Texas.

The new fees are part of a settlement between Visa, MasterCard and nine big banks. The settlement gives retailers the option to tack on a surcharge if a customer uses a credit card. The retailer can charge 1.5 to 3 percent of the total purchase, enough to cover the processing costs.

The fee doesn't apply to debit cards and it will still be illegal to charge fees in 10 states. Again, stores will have the choice to either get stuck footing the bill for the swipe fees, or risk transferring the cost to their customers, possibly driving away business.

Walmart said in a statement that it would cost customers tens of billions of dollars each year.